In every year there is one day that occurs 53 times rather than the usual 52 (7 days times 52 weeks a year is 364 days, not 365). In 2009 this "extra day" falls on a Thursday – one of the two biggest paydays of the year. This means that if you pay your employees on a bi-weekly Thursday basis, they will see 53 paydays instead of the usual 52 in 2009. If your offer of employment is an annualized number (i.e., "you will receive $100,000 per annum") then this anomaly is not a legal issue for you but, of course, may result in an employee relations issue. However, if you offer pay on a bi-weekly basis, i.e., "you will receive $2,000 every other Thursday ") you may contractually be obligated to pay the person 27 pay cycles for a calendar year 2009.
Of course, from an accounting standpoint, most employers divide base salary by the number of pay periods resulting in the payment for the particular pay period. However, an employer who pays a bi-weekly Thursdays basis, will either have to pay out an extra paycheck for 2009 or divide the annualized payment by 27 – which will result in a reduction of the employee's pay in each of the 27 pay periods. For example, a company with 50 salaried workers making $2,000 every two weeks would incur an extra $100,000 in salaries for calendar year 2009 – hardly an insignificant number in light of the recent economic woes. It might be prudent to examine your offer letters and employment agreement in light of this calendar anomaly.
By the way, for those of you who pay employees on Fridays, this issue will be on your plate in 2010.